Solid sampler, apparatus and method

ABSTRACT

Solid sampler having a tray with a plurality of sample boats carried by the tray and containing samples to be analyzed with means for introducing the boats into a pyrolysis tube and removing the boats from the pyrolysis tube. The apparatus is a microcoulometric titrating system which includes the solid sampler combined with a pyrolysis furnace and a titration cell. The method involves the steps of utilizing the solid sampler in a microcoulometric titration system for reductive-type analyses and oxidative-type analyses.

United States Patent Stephen s 1 Mar. 7, 1972 [54] SOLID SAMPLER, APPARATUS AND Primary Examiner-Morris O. Wolk METHOD Assistant Examiner-Elliott A. Katz [72] lnventor: Thomas M. Stephens, Menlo Park, Calif. Attorney-Hem Hohbach Test Albrmon & Herbert [73] Assignee: Dohrmann Instruments Company, Moun- [57] ABSTRACT tain View, Calif. Solid sampler having a tray with a plurality of sample boats Flledi 20, 1969 carried by the tray and containing samples to be analyzed with [21] APPL No: 800,946 means for introducing the boats into a pyrolysis tube and removing the boats from the pyrolysis tube. The apparatus is a microcoulometric titrating system which includes the solid [52] 3g g i sampler combined with a Pyrolysis furnace and a titration cell. [51] m Cl G01 31/12 Goln 31/16 The method involves the steps of utilizing the solid sampler in 58 Field .i'iii 55/530 230 PC 253 253 PC a micmmubmetric System for reductive-We 25 9; 0 1 v analyses and oxidative-type analyses.

[ 5 6] References Cited 26 Claims, 13 Drawing Figures UNITED STATES PATENTS Varadi et al. ..23/259 PATENTEDMAR H972 3,647,385

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' INVENTOR. Thomas M. Stephens BY (llllllllll PATENTED 71973 3,647, 385

SHEET 2 OF 5 INVENTOR. Thomas M. Stephens M, WM 34 26 mym/ Aflorneys SHEET 3 [IF 5 Ill my vv M FL i x flirt!!! fill!!! PATENTEDMAR 71972 BY iii/a, )L/ mfm:

PATENTEDHAR 71972 3,647, 385

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. INVENTOR. Thomas M. Stephens 9%, W mym Attorneys PATENTEUMAR (I972 3,647. 385

, INVENTOR.

' Thomas M. Stephens BY rforneys SOLID SAMPLER, APPARATUS AND METHOD BACKGROUND OF THE INVENTION In making chemical analyses and in particular in making such analyses in microcoulometric titration systems it has been difiicult or impossible to handle semiviscous samples and solids. There is therefore a need for a new and improved apparatus and method for handling such materials to facilitate making chemical analyses.

SUMMARY OF THE INVENTION AND OBJECTS The solid sampler consists of a main body assembly which forms a gastight chamber and which has a feed-through passage formed therein. A holder is mounted in the body for movement relative to the body. A tray is removably mounted on the holder and is adapted to carry a plurality of sample boats. Means is mounted on the main body assembly operable from the exterior of the main body assembly for engaging the boats one by one and moving them relative to the tray through said feed-through passage. The apparatus includes a pyrolysis furnace which has a pyrolysis tube mounted therein which is connected to the feed-through passage in the main body assembly so that the boats can be introduced directly into the pyrolysis tube from the main body assembly. The apparatus also includes a titration cell for making coulometric analyses of the samples carried by the boats. Two different types of pyrolysis tubes, one for a reductive-type analysis and the other for an oxidative-type analysis can be used. The method comprises the steps which are utilized for operating the solid sampler in conjunction with a reductive-type analysis and for an oxidative-type analysis.

In general, it is an object of the present invention to provide a solid sampler and apparatus and method which makes it possible to handle and analyze liquid samples, semiviscous samples and solid samples.

Another object of the invention is to provide a sampler, apparatus and method of the above character which can be utilized with reductive-type and oxidative-type analyses.

Another object of the invention is to provide a sampler and apparatus of the above character in which a plurality of sample boats can be utilized.

Another object of the invention is to provide a sampler and apparatus of the above character in which the boats can be readily loaded and in which they can be readily inserted and removed from the pyrolysis tube.

Additional objects and features of the invention will appear from the following description in which the preferred embodiments are set forth in detail in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a front elevational view of apparatus incorporating the present invention and showing the use of a solid sampler.

FIG. 2 is an end elevational view of the apparatus shown in FIG. I looking along the line 2-2.

FIG. 3 is a cross-sectional view of the main body assembly of the solid sampler.

FIG. 4 is a cross-sectional view taken along the line 44 of FIG. 3.

FIG. 5 is a side elevational view and shows portions of the solid sampler and the pyrolysis tube with certain portions of the same being in cross section.

FIG. 6 is a view similar to a portion of the view shown in FIG. 5 showing the manner in which the solid sampler is used.

FIG. 7 is a side view taken along the line 7-7 of FIG. 6.

FIG. 8 is a cross-sectional view taken along the line 88 of FIG. 5.

FIG. 9 is a cross-sectional view taken along the line 99 of FIG. 5.

FIG. 10 is a cross-sectional view taken along the line 10-10 of FIG. 3.

FIG. 11 is a side elevational view partially in cross section of the pyrolysis tube utilized for an oxidative type analysis.

FIG. 12 is a cross-sectional view taken along the line 13 13 of FIG. 1 1.

FIG. 13 is a cross-sectional view taken along the line 12-12 of FIG. 1 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus which is shown in the drawings consists of a solid sampler 16 which is adapted to supply the samples to be analyzed as hereinafter described to a pyrolysis furnace 17. The apparatus also includes a strip chart recorder 18 and a control console 19. A titration cell assembly 21 is connected to the pyrolysis furnace 17.

The solid sampler 16 consists of three assemblies. The first can be termed a main body assembly 26, the second a barrel assembly 27 and the third an enclosure assembly 28. The main body assembly 26 consists of a cylindrical body 29 which is provided with a diametrically aligned feed-through passage or bore 31 and an access bore 32. A bottom plate 33 is secured to the body 29 by screws 34. A gastight seal is formed between the bottom plate 33 and the body 29 and consists of an O-ring 36 disposed in an annular groove 37 provided in the body 29. The bottom plate 33 is provided with a bore 38 through which gases can be vented. The plate is also provided with a bore 39 which is inclined at an angle with respect to the plane of the plate as for example an angle of 7 from the vertical.

The main body assembly includes a cover assembly 41. The cover assembly 41 consists of upper and lower retainer rings 42 and 43 which have mounted therebetween a transparent cover plate 44 formed of a suitable material such as plastic or glass. The retainer rings 42 and 43 are fastened together by cap screws 46. A gastight seal is formed between the cover plate 44 and the retainer rings 42 and 43 by an O-ring 47 disposed in an annular groove 48 in the retainer ring 43. Means is provided for removably securing the cover assembly 41 to the body 29 and consists of a plurality of bolts 49 which are disposed in slots 51 spaced circumferentially around the cover assembly 41, the body 29 and the bottom plate 33. The bolts 49 are provided with wing nuts 52 to facilitate ready removal and placement of the cover assembly 41. A gastight seal is formed between the cover assembly 41 and the body 29 by an O-ring 53 disposed in an annular groove 54 provided in the body 29.

As can be seen from the drawings, the various parts of the main body assembly 26 hereinbefore described form a gastight cylindrical chamber 56.

The main body assembly 26 also includes a holder 58 which is rotatably mounted in the bottom plate 33. The holder 58 consists of a flat circular plate 59 which has a shaft or a stem 61 mounted thereon and extending at right angles to the plane of the plate. The plate 59 is provided with a centrally disposed boss 62 extending upwardly therefrom and a pair of pins 63 which are also upstanding therefrom and which are located diametrically on the plate 59. The shaft 61 is rotatably carried by a fitting 64 which is threaded into the bore 39 in such a manner that the plane extends at an angle of approximately 7 from the horizontal for a p$rpose hereinafter described. A gastight seal is formed between the shaft 61 and the fitting 64 by an O-ring 66 which is clamped into place by a retainer nut 67. The holder 58 is adapted to be rotated by a knob 68 mounted on the shaft 61.

A fitting 69 is fitted into the bore 38 of the bottom plate 33 and is connected to a vent pipe 71. An inlet assembly 72 is mounted in the hole 73 provided in the glass cover plate 44. The inlet assembly 72 carries a septum 74 through which materials can be introduced into the chamber 56 by use of a hypodermic needle as hereinafter described.

A sample plate or tray 81 is adapted to be placed within the chamber 56 upon the holder 58 as is shown particularly in FIG. 3. The sample plate 81 is adapted to carry a plurality of sample boats 82. The sample plate 81 is in the form of a circular plate 83 and is provided with a centrally disposed hole 84 which is adapted to accommodate the boss 62 and a pair of diametrically aligned holes 86 which are adapted to receive the pins 63 so that the plate 83 is supported by and rotates with the holder 58. The plate 83 is also provided with a pair of larger holes 87 which are also spaced diametrically of the plate and which serve as finger holes for grasping the plate. The plate 83 is also provided with a large slot 88 which opens through the outer edge of the plate and which extends in wardly to a point adjacent one of the holes 86. The plate 83 is also provided with a plurality of radially extending milled slots 89 which open through the top surface 90 of the plate 83. The slots 89 extend from the outer margin of the plate inwardly to a raised annular portion 83a provided on the top surface of the plate. Any desired number of slots 89 can be provided. In the embodiment shown, it has been convenient to provide seventeen of such slots which are equally spaced about the circumference of the plate 83. Means is provided in the slots 89 for retaining the boats and consist of suitable means such as small metal rods or pins 91 formed of a suitable material such as brass which are soldered in the grooves or slots 89 and form track sections for the boats. The pins 91 are of such a diameter so that they extend for a substantial distance above the top surface 90 of the plate 83. q

The sample boats 82 can be formed of any suitable material. For example, two materials found to be particularly desirable are quartz and alumina. In addition, for certain applications, it may be desirable to use platinum. The boats 82 are generally formed from a solid block or body 94 of material and are generally semicircular in cross section as can be seen from FIG. 10. Thus the boats are provided with a semicylindrical outer bottom surface 96 and a planar top surface 97. A sample cavity or recess 98 is formed in the body 94 and opens through the top surface 97. The cavity can be of any desired configuration as for example rectangular as shown. The body 94 is also provided with a slot or recess 99 extending laterally of the body 94 adjacent one end of the same whereas the cavity is disposed in the remaining portion of the body. The body 94 is provided with a groove 101 extending longitudinally of the body which opens through the center of the outer bottom surface 96 and is of such a size that it can accommodate the pins or rods 91 provided on the sample plate 81. As can be seen from FIG. 10, the groove 101 serves as a track for the boat 82 and also serves to prevent the boat from tipping over when it is resting upon the sample plate 81. The pins 91 and the groove 101 form cooperative mating means for guiding the boats. As can be seen from FIG. 4, the boat is of a length which is slightly less than the length of the pins or rods 91 carried by the sample plate.

The barrel assembly 27 consists of a barrel 104 formed of a suitable material such as stainless steel which has one end mounted in a fitting 106 threaded into a bore 32 provided in the body 29. The barrel 104 is held in place by a Swagelok seal formed of a nut 107 and a sealing ring 108. Another fitting 109 is mounted in the other end of the tube or barrel 104 and has a small rod 111 slidably mounted therein. A nut 113 which carries an O-ring 114 is threaded onto the fitting 109. A flanged washer 115 is secured to the rod 111 by a set screw 116. A flange 117 is provided on the barrel 104 adjacent the outer end thereof. A knob 118 is mounted on the outer end of the rod 111 to facilitate movement of the push rod 1 11. An inlet assembly 121 is mounted adjacent the outermost end of the barrel 104 and is connected to an inlet pipe 122 which can be utilized for introducing a gas into the chamber 56 as hereinafter described.

The rod 111 is provided with a threaded end portion 111a which is adapted to engage a valve assembly 124. The valve assembly 124 consists of a valve member 126 which is provided with a central bosslike portion 126a that has a threaded bore which is adapted to receive the threaded portion 111a of the pushrod 111. The valve member 126 carries a sealing member 127. The rod 111 and the parts hereinbefore described comprise what can be called a pushrod assembly 128.

The pushrod assembly 128 also includes a tip assembly 129. The tip assembly 129 consists of a rod 131 formed of a suitable material such as stainless steel which is threaded onto a threaded extension 126b provided on the valve member 126 and extends in axial alignment with the rod 111. A small elongate rod 132 of suitable material such as quartz is carried by the rod 131 and also extends in an axial direction with respect to the rod 111. The rod 132 is provided with downturned or hooklike portion 132a as shown particularly in FIG. 5. As also can be seen from FIG. 5, the downturned or hooklike portion 132a is adapted to seak in the groove 99 provided in the boat 82. Alternatively, if desired, a collet assembly can be provided on the rod 131 for receiving the quartz rod 132.

As can be seen from FIG. 1, the main body assembly 26 which has the barrel assembly 27 mounted thereon is carried by the enclosure assembly 28. The enclosure assembly 28 consists of a case 136 which is provided with a front access door 137. A plurality of fittings and suitable piping are provided within the case 136 to facilitate the venting and switching of gases.

The pyrolysis furnace 17, the strip chart recorder 18, the

control console 19 and the titration cell 21 are substantially conventional and therefore will not be described in detail. By way of example, they can be of the type supplied by Dohrmann Instruments Company of Mountain View, CaL, as a type C-200 microcoulometer. The pyrolysis furnace 17 differs slightly in that it has been provided with an additional heater section so that the entire length of the furnace is heated. A special pyrolysis tube 141 is mounted in the furnace and is shown in detail in FIGS. 5, 8 and 9. The pyrolysis tube 141 is of a type which is used for reductive type analyses and is generally described in copending application Ser. No. 697,901 filed on Jan. 15, 1968, now US. Pat. No. 3,565,583. The pyrolysis tube 141 however does differ from the pyrolysis tube disclosed herein in that the present pyrolysis tube 141 has been modified to function with the solid sampler 16. Thus, the pyrolysis tube 141 which is normally formed of quartz is provided with a long thin quartz rod 142 that is secured to the bottom of the inner surface of the wall forming the tube 141 and extends inwardly of the tube from the inlet end of the tube shown particularly in FIG. 5. A formed stop member 143 is mounted within the pyrolysis tube 141 adjacent the end of the rod 142. The pyrolysis tube 141 is provided with an inlet 144 and an outlet 146. In addition it is provided with a septum inlet 147 formed integral with the pyrolysis tube and which carries a septum 148. The septum inlet 147 is also provided with a socket inlet 149. A suitable fitting 151 such as a Swagelok fitting is provided for connecting the inlet end of the pyrolysis tube 141 to the feed-through bore or passage 31 provided in the body 29.

Another pyrolysis tube 156, 'which is suitable for usein the pyrolysis furnace 17, is shown in FIGS. 11, 12 and 13 and is utilized for oxidativedype analyses. It also is formed of quartz. The pyrolysis tube 156 consists of an outer tube 157 and an inner tube 158 which has a diameter substantially less than the diameter of the outer tube. The inner tube 158 is provided with a small quartz rod 159 which is secured to the lower inner surface of the same and extends from an inlet 161 provided by the tube 158 throughout a substantial portion of the length of the inner tube 158. A forked stop member 162 extends vertically within the tube 158 and is adjacent the end of the rod 159. The inner end of the tube 158 is closed and is provided with four circumferentially spaced slots 163 adjacent the end of the tube 158. A septum inlet 166 is provided for the inner tube 158 and carries a septum 167. The septum inlet 166 also carries a socket inlet 168. A separate socket inlet 169 is provided for the outer tube 157. The large tube 157 forms an outlet 171.

The outlets of the pyrolysis tubes hereinbefore described are connected to the titration cell assembly 21, in a conventional manner.

Movable means is provided for retaining the valve member 124 in a closed position with respect to the inlet of the pyrolysis tube which is being utilized and consists of a clamp 176. The clamp 176 is formed of a pair of forklike members 177 and 178 which are pivotally interconnected by a pin 179 extending through arms 181 and 182 secured to the members 177 and 178 and extending at right angles thereto. A spring 183 is mounted on boses 184 provided on the members 177 and 178 and yieldably urges the members 177 and 178 to an open position.

In addition to a vent valve which can be provided within the enclosure assembly 28, there can be provided a switch valve which can be utilized for switching a reactant gas from one passage to another as for example from the inner tube 158 to the outer tube 157 of the pyrolysis tube 156.

The switch valve can also be utilized for simultaneously switching from one gas to another, thus helium can be bled into the outer tube 157 and oxygen into the inner tube 158 and conversely by operating the switch valve helium can be passed through the inner tube 158 and oxygen through the outer tube 157.

Operation of the solid sampler and apparatus in performing the method of the present invention may now be briefly described as follows. Let it be assumed that the appropriate pyrolysis tube is in position. A thorough check is then made to see that there are no leaks in the apparatus. The pyrolysis tube is then purged to remove all air from it by passing a gas such as helium or argon through the pyrolysis tube by introducing the gas into the tube 122 of the barrel assembly. If the reductivetype pyrolysis tube is being utilized, hydrogen would then be passed through the pyrolysis tube to condition the catalyst within the tube. As soon as this has been accomplished and it is now desired to run certain samples in the apparatus, the sample tray or plate 81 is positioned so that the large slot 89 is generally in registration with the feed-through passage to permit the valve assembly 124 to be moved into engagement with the inlet end of the pyrolysis tube by grasping the knob 118 and pushing the rod 111 inwardly. Movement is continued until the sealing member 127 carried by the valve member 126 engages the inlet end of the pyrolysis tube as shown in FIG. 5. The clamp 176 is then installed to hold the valve assembly 124 in place so that no leaks can occur into the pyrolysis tube. This seals the chamber 56 from the pyrolysis tube. If hydrogen has been used as the reactant gas, the hydrogen is vented by running helium or argon through the barrel assembly and out the vent.

The cover assembly 41 can then be removed by loosening the wing nuts 52 and shifting the bolts 49 out of the groove and lifting the cover assembly upwardly. The clamp is then moved from the barrel assembly to the valve assembly 124 and clamped at this point. The pushrod 111 is then unthreaded from the valve assembly 124 by rotation of the knob 118 in a counterclockwise direction and then withdrawn out of the chamber 56. Thereafter, the sample tray or plate 81 can be removed by inserting the fingers into the holes 87 and lifting the sample plate upwardly off of the holder 58 and out of the chamber 56.

With the sample tray of the type shown, 17 boats 82 can be loaded onto the tray. As hereinafter explained, only of the boats are loaded with samples in the cavities 98. The material whether it is solid or a semiviscous material is weighed and loaded into the boats. Two blank boats are placed on the tray and then the tray is loaded back into the body assembly by placing it on the holder 58 so that the two pins 63 engage the holes 86 provided in the sample tray.

As soon as the sample plate or tray 81 is in place with the slot 89 in registration with the valve assembly 124, the pushrod assembly 128 is moved inwardly and the pushrod 111 is threaded into the valve assembly 124. The pinch clamp 176 is then removed and then is installed externally of the main body assembly 26 on the barrel assembly 27 by having members 177 and 178 engaging the flanged washer 115 and the flange 117 provided on the barrel 104 which again causes pressure to be applied to the seal 127 to keep the inlet end of the pyrolysis tube closed. Alternatively the clamp 176 can engage the nut 113 and the flange 117 on the barrel 104 can be omitted.

After these operations have been completed, the cover assembly 41 can be replaced and the wingnuts 22 tightened to secure the cover. It is now necessary to purge the chamber 56 by passing helium, argon or other inert gas through the pipe 122 into the barrel assembly and out through the vent pipe 71 provided in the enclosure assembly 28. As soon as all the air has been purged from the chamber 56, the reactant gas which is to be utilized in the pyrolysis tube is passed into the chamber 56 to purge any inert gas which is within the chamber. As soon as the inert gas has been removed from the chamber 56, a valve (not shown) is closed to prevent further venting of the gases from the chamber. At this point, the pinch clamp 176 is removed from the barrel assembly and the pushrod assembly 128 is pulled rearwardly to break the seal between the chamber 56 and the pyrolysis tube.

The effect of breaking the seal can be observed on the chart recorder 18 and as soon as a stabilized condition has been observed, the apparatus is now ready for the testing or analysis of the samples carried by the sample boats 82. The operator grasps knob 68 and rotates the sample plate 81 until the number 1 boat is in alignment with the feedthrough passage 31. It will be noted that the sample tray is inclined in such a manner that the rod 91 underlying the sample boat number 1 is in alignment with the rod 142 provided in the pyrolysis tube 141 and that the sample boat is generally in line with the feedthrough passage 31. The sample boat number 1 is then picked up by moving the push rod assembly inwardly until the hook portion 132a engages the recess 99 in boat number 1. As soon as this has been accomplished, the pushrod assembly is operated to advance the pushrod 111 so that the tip 132 is advanced into the pyrolysis tube carrying with it the boat number 1. The boat is advanced into the pyrolysis tube until it comes into engagement with the stop 143. The boat is then left in the furnace until the sample contained therein has been consumed in the reaction taking place within the pyrolysis tube, as can be readily observed by watching the tracing of the strip chart recorder 18. As soon as the reaction has been completed, the boat is removed by withdrawing the pushrod 111 and bringing the boat back onto its pin 91 on the sample tray 81. The tip 132 is then removed from the boat 82 and then the sample tray is advanced so that the next sample boat is in alignment with the feed-through passage 31. The same procedure is then carried out until all of the samples have been run. The boats have been numbered on the tray to make it possible for the operator to keep track of the samples as they are run.

It was previously pointed out that it was desirable to leave two of the sample boats empty or as blanks. it is normally desirable to run these two blank boats into the pyrolysis furnace to establish the amount of contaminants which were picked up from the air or other sources during the time that the boats were being loaded with the samples. This information provides the background level which would have to be subtracted from the results obtained from the other samples to provide the correct results.

After all the samples have been run, the sample plate would be rotated until the large slot 88 is in registration with the feed-through passage 31. At this point, the push rod assembly is advanced to move the valve assembly 124 into engagement with the inlet end of the pyrolysis tube to seal the same. The pinch clamp 176 is placed on the barrel assembly to hold the valve assembly 124 in place. At this time an inert gas is passed into the chamber 56 and the main body assembly and the vent pipe 71 is opened so that the reactant gas is removed. As soon as this has been accomplished, the cover assembly 41 is removed. The clamp 176 is then shifted to engage the valve assembly 124 and the fitting 151. The pushrod assembly 128 is then unthreaded from the valve assembly and withdrawn after which the sample tray 81 is removed from the chamber 56. Thereafter, the same sequence of steps can be repeated.

In the foregoing construction the plate 81 was provided with the large slot 88 to provide clearance for the rod 111. Altematively, the chamber 56 can be made deeper to provide additional space below the plate 81 so that the holder 58 can be moved downwardly by grasping the knob 68 to provide clearance for the rod 111. The O-ring 66 would serve to hold the holder 61 in the desired raised or lowered position.

The foregoing description has been principally in conjunction with the reductive-type pyrolysis tube. However, the mode of operation with the oxidative-type pyrolysis tube is very similar, with the exception that oxygen is utilized as a reactant gas. The boats are introduced into the smaller tube 158 in the same manner in which they are introduced into the tube 141.

It will be noted that the main body assembly 26 has been provided with a septum inlet assembly 72 which makes it possible by the use of a hypodermic needle to deposit a sample directly into a boat while the boat is carried by the tray within the chamber 56. This makes it possible to vent light solvents without running them down the pyrolysis tube. As hereinbefore explained, the pyrolysis tubes are also provided with septum inlets which also makes it possible to introduce samples by way of hypodermic needles directly into the pyrolysis tubes when desired.

It is apparent from the foregoing that there has been provided a solid sampler, apparatus and method which has many advantages and which is particularly desirable for the testing or analysis of solid samples and semiviscous samples. The construction of the apparatus is such that the pyrolysis tube can be readily sealed from the chamber 56 thereby permitting ready loading and unloading without contaminating the catalyst or other agents carried by the pyrolysis tube. The construction of the apparatus is such that the boats will remain in an upright position and will not tip over in the pyrolysis tube. In addition, the pyrolysis tube and the boats have been cons,ructed so that the boats cannot become lost in the pyrolysis tube. The boats are continuously tracked while they are carried either by the tray or within the pyrolysis tube. The boats cannot be advanced too far into the pyrolysis tube because of the stops provided in the tube.

lclaim:

1. In a sampler, a main body assembly forming a gastight chamber and having a feed-through passage therein, a holder mounted in the chamber for movement relative to the main body assembly, a sample tray mounted on the holder for movement with the holder, a plurality of sample boats carried by the sample tray, means secured to the holder and extending out of the chamber and operable from the exterior of the main body assembly for shifting the holder to move the tray with all of the boats thereon to permit selection of the sample boats in any desired order to position successive sample boats in registration with the feed-through passage and means mounted on the main body assembly operable from the exterior of the main body assembly for engaging the sample boats one by one and removing them from the sample tray and moving them through said feed-through passage.

2. A sampler as in claim 1 wherein said holder is rotatably mounted in said body, said holder being inclined at an angle so that said sample tray carriedthereby is also inclined at an angle and has at least one portion thereof at the same general level as the feed-through passage in said main body assembly.

3. A sampler as in claim 1 wherein said main body assembly includes means permitting said sample boats to be loaded while carried by said sample tray and disposed within said chamber.

4. A sampler as in claim 1 wherein said main body assembly includes a removable cover assembly to permit removal of said sample tray from said chamber to permit loading of the boats carried by the sample tray.

5. A sampler as in claim 1 wherein said sample tray is circular in fon'n, said sample tray having a plurality of circumferentially spaced radially extending track sections mounted thereon, and wherein said sample boats are fonned with recesses which are adopted to fit over the track sections.

6. A sampler as in claim 1 wherein said boats are generally semicircular in cross section with an outer lower semicylindrical surface and wherein said grooves open through said semicylindrical surface, said sample boats also having a planar upper surface and wherein said boats are formed with a cavity opening through the upper surface and a groove opening through the upper surface.

7. A sampler as in claim 1 wherein said holder is inclined at an angle with respect to the vertical and wherein said tray has at least one portion of same which is at the level of the feedthrough passage.

8. A sampler as in claim 1 wherein said sample tray and said boats carry cooperative mating means whereby said boat can only travel in a predetermined path with respect to said sample tray.

9. A sampler as in claim 8 wherein said cooperative mating means is formed of elongate track sections carried by the sample tray and grooves formed in the sample boats, said grooves accommodating said track sections.

10. A sampler as in claim 1 wherein each sample boat is provided with a cavity for receiving a sample and wherein each sample boat is also provided with a recess and wherein said means for engaging the boats includes a hooklike member adapted to seat in the recess provided in said boat. 11. A sampler as in claim 10 wherein said means mounted on the body assembly from the exterior of the main body assembly includes a barrel assembly mounted on the main body assembly, a pushrod slidably mounted in said barrel assembly, said pushrod having a hooklike member adapted to seat in the groove in said sample boats so that said sample boats can be advanced through said feed-through passage by operation of said pushrod.

12. A sampler as in claim 1 together with a reaction tube, means connecting the reaction tube to the feed through passage in the body, said reaction tube having track means therein said track means being formed to accommodate said boats as said boats are advanced through said feed-through passage into said reaction tube.

13. A sampler as in claim 12 together with stop means provided in said reaction tube to prevent said sample boat from being advanced more than a predetermined distance into the reaction tube.

14. A sampler as in claim 1 wherein said means mounted on the main body assembly operable from the sample exterior of the main body assembly for engaging the boats includes a barrel assembly mounted on the body assembly, a pushrod slidably mounted in said barrel assembly, said barrel assembly being of such a length so that said pushrod can be removed from said chamber to permit said sample tray to be removed from the chamber.

15 A sampler as in claim 14 together with a valve member carried by the push rod assembly, said valve member being movable into position to close the feed-through passage to isolate the reaction tube from the chamber in the main body assembly.

16. A sampler as in claim 15 wherein said holder and sample tray carried thereby are disposed at an angle and wherein said tray is provided with a slot in the outer margin thereof, said tray being movable into position in which said slot is in registration with said feed-through passage to permit said valve assembly to be moved into engagement with the feed-through passage to seal the chamber from the reaction tube.

17. In a pyrolytic apparatus, a sampler comprising a main body assembly forming a gastight chamber and having a feedthrough passage therein, a holder mounted in the body assembly for movement relative to the body assembly, a sample tray mounted on said holder for movement with said holder, a plurality of sample boats carried by the sample tray, means secured to the holder and extending out of the chamber and operable from the exterior of the main body assembly for shifting the holder to move the tray with all of the sample boats thereon to permit selection of the sample boats in any desired order to position successive sample boats in registraytion with the feed-through passage, means mounted on the main body assembly operable from the exterior of the main body assembly for engaging the sample boats one by one and for moving them relative to the sample tray through said feedthrough passage, a pyrolysis furnace having a pyrolysis tube mounted therein, said pyrolysis tube having an inlet and an outlet, means connecting the inlet of the pyrolysis tube to the feed-through passage of the sampler whereby said sample boats can be advanced into the pyrolysis cell from the feedthrough passage, and a titration cell assembly connected to the output of the pyrolysis tube.

18. Apparatus as in claim 17 wherein said means mounted on the main body assembly operable from the exterior of the main body assembly includes a pushrod assembly and valve means carried by the pushrod assembly, said pushrod assembly being movable into a position so that said valve means can be moved into engagement with the feed-through passage to isolate said chamber from said pyrolysis tube.

19. Apparatus as in claim 18 wherein said sample tray is provided with a large groove adapted to be moved into registration with said feed-through passage whereby said valve member may be moved into engagement to seal off said feedthrough passage.

20. Apparatus as in claim 17 wherein said pyrolysis tube is generally circular in cross section and wherein said sample boats have a'curved bottom surface generally corresponding to the radius of curvature of the pyrolysis tube, and means carried by the sample tray and by the pyrolysis tube for maintaining the sample boats in a predetermined upright position on the sample tray and in the pyrolysis tube.

21. Apparatus as in claim 20 wherein said means for maintaining said sample boats in an upright position includes track sections carried by the tray and by the pyrolysis tube and wherein said sample boats are formed with grooves adapted to seat on said track sections.

22. Apparatus as in claim 21 wherein said sample tray is in the form of a circular plate and wherein said track sections are mounted on the sample tray in circumferentially spaced radially extending positions.

23. Apparatus as in claim 22 wherein said holder and said sample tray are inclined so that said sample tray is inclined from the horizontal and has at least one portion thereof at a level with the feed-through passage.

24. A boat comprising a body, said body having a generally planar upper surface and a generally semicylindrical bottom outer surface, said body being formed with a cavity for receiving a sample through said upper surface, said body also being formed with a groove separate from the cavity opening through the upper surface.

25. A boat as in claim 24 wherein said body is formed with a recess extending longitudinally of the same.

26. A method for analyzing solid and semiviscous materials in a pyrolysis furnace having a pyrolysis tube and a chamber separate from the pyrolysis tube with a feed-through passage connecting the chamber to the pyrolysis tube comprising, establishing a gastight seal between the chamber and the pyrolysis tube, passing an inert gas through the chamber and through the pyrolysis tube, passing a reactive gas through the chamber and through the pyrolysis tube, sealing off the pyrolysis tube from the chamber, placing the samples in the chamber, closing the chamber, purging the chamber with an inert gas, introducing a reactive gas into the chamber, removing the gastight seal between the pyrolysis tube and the chamber, introducing the samples within the chamber into the pyrolysis tube in sequence until the samples have been analyzed, establishing a gastight seal between the chamber and the pyrolysis tube, introducing an inert gas into the chamber, and thereafter removing the sample carriers from the chamber. 

2. A sampler as in claim 1 wherein said holder is rotatably mounted in said body, said holder being inclined at an angle so that said sample tray carried thereby is also inclined at an angle and has at least one portion thereof at the same general level as the feed-through passage in said main body assembly.
 3. A sampler as in claim 1 wherein said main body assembly includes means permitting said sample boats to be loaded while carried by said sample tray and disposed within said chamber.
 4. A sampler as in claim 1 wherein said main body assembly includes a removable cover assembly to permit removal of said sample tray from said chamber to permit loading of the boats carried by the sample tray.
 5. A sampler as in claim 1 wherein said sample tray is circular in form, said sample tray having a plurality of circumferentially spaced radially extending track sections mounted thereon, and wherein said sample boats are formed with recesses which are adopted to fit over the track sections.
 6. A sampler as in claim 1 wherein said boats are generally semicircular in cross section with an outer lower semicylindrical surface and wherein said grooves open through said semicylindrical surface, said sample boats also having a planar upper surface and wherein said boats are formed with a cavity opening through the upper surface and a groove opening through the upper surface.
 7. A sampler as in claim 1 wherein said holder is inclined at an angle with respect to the vertical and wherein said tray has at least one portion of same which is at the level of the feed-through passage.
 8. A sampler as in claim 1 wherein said sample tray and said boats carry cooperative mating means whereby said boat can only travel in a predetermined path with respect to said sample tray.
 9. A sampler as in claim 8 wherein said cooperative mating means is formed of elongate track sections carried by the sample tray and grooves formed in the sample boats, said grooves accommodating said track sections.
 10. A sampler as in claim 1 wherein each sample boat is provided with a cavity for receiving a sample and wherein each sample boat is also provided with a recess and wherein said means for engaging the boats includes a hooklike member adapted to seat in the recess provided in said boat.
 11. A sampler as in claim 10 wherein said means mounted on the body assembly from the exterior of the main body assembly includes a barrel assembly mounted on the main body assembly, a pushrod slidably mounted in said barrel assembly, said pushrod having a hooklike member adapted to seat in the groove in said sample boats so that said sample boats can be advanced through said feed-through passage by operation of said pushrod.
 12. A sampler as in claim 1 together with a reaction tube, means connecting the reaction tube to the feed through passage in the body, said reaction tube having track means therein said track means beinG formed to accommodate said boats as said boats are advanced through said feed-through passage into said reaction tube.
 13. A sampler as in claim 12 together with stop means provided in said reaction tube to prevent said sample boat from being advanced more than a predetermined distance into the reaction tube.
 14. A sampler as in claim 1 wherein said means mounted on the main body assembly operable from the sample exterior of the main body assembly for engaging the boats includes a barrel assembly mounted on the body assembly, a pushrod slidably mounted in said barrel assembly, said barrel assembly being of such a length so that said pushrod can be removed from said chamber to permit said sample tray to be removed from the chamber. 15 A sampler as in claim 14 together with a valve member carried by the push rod assembly, said valve member being movable into position to close the feed-through passage to isolate the reaction tube from the chamber in the main body assembly.
 16. A sampler as in claim 15 wherein said holder and sample tray carried thereby are disposed at an angle and wherein said tray is provided with a slot in the outer margin thereof, said tray being movable into position in which said slot is in registration with said feed-through passage to permit said valve assembly to be moved into engagement with the feed-through passage to seal the chamber from the reaction tube.
 17. In a pyrolytic apparatus, a sampler comprising a main body assembly forming a gastight chamber and having a feed-through passage therein, a holder mounted in the body assembly for movement relative to the body assembly, a sample tray mounted on said holder for movement with said holder, a plurality of sample boats carried by the sample tray, means secured to the holder and extending out of the chamber and operable from the exterior of the main body assembly for shifting the holder to move the tray with all of the sample boats thereon to permit selection of the sample boats in any desired order to position successive sample boats in registration with the feed-through passage, means mounted on the main body assembly operable from the exterior of the main body assembly for engaging the sample boats one by one and for moving them relative to the sample tray through said feed-through passage, a pyrolysis furnace having a pyrolysis tube mounted therein, said pyrolysis tube having an inlet and an outlet, means connecting the inlet of the pyrolysis tube to the feed-through passage of the sampler whereby said sample boats can be advanced into the pyrolysis cell from the feed-through passage, and a titration cell assembly connected to the output of the pyrolysis tube.
 18. Apparatus as in claim 17 wherein said means mounted on the main body assembly operable from the exterior of the main body assembly includes a pushrod assembly and valve means carried by the pushrod assembly, said pushrod assembly being movable into a position so that said valve means can be moved into engagement with the feed-through passage to isolate said chamber from said pyrolysis tube.
 19. Apparatus as in claim 18 wherein said sample tray is provided with a large groove adapted to be moved into registration with said feed-through passage whereby said valve member may be moved into engagement to seal off said feed-through passage.
 20. Apparatus as in claim 17 wherein said pyrolysis tube is generally circular in cross section and wherein said sample boats have a curved bottom surface generally corresponding to the radius of curvature of the pyrolysis tube, and means carried by the sample tray and by the pyrolysis tube for maintaining the sample boats in a predetermined upright position on the sample tray and in the pyrolysis tube.
 21. Apparatus as in claim 20 wherein said means for maintaining said sample boats in an upright position includes track sections carried by the tray and by the pyrolysis tube and wherein said sample boats are formed with grooves adapted to seat on said track sections.
 22. Apparatus as in claim 21 wherein said sample tray is in the form of a circular plate and wherein said track sections are mounted on the sample tray in circumferentially spaced radially extending positions.
 23. Apparatus as in claim 22 wherein said holder and said sample tray are inclined so that said sample tray is inclined from the horizontal and has at least one portion thereof at a level with the feed-through passage.
 24. A boat comprising a body, said body having a generally planar upper surface and a generally semicylindrical bottom outer surface, said body being formed with a cavity for receiving a sample through said upper surface, said body also being formed with a groove separate from the cavity opening through the upper surface.
 25. A boat as in claim 24 wherein said body is formed with a recess extending longitudinally of the same.
 26. A method for analyzing solid and semiviscous materials in a pyrolysis furnace having a pyrolysis tube and a chamber separate from the pyrolysis tube with a feed-through passage connecting the chamber to the pyrolysis tube comprising, establishing a gastight seal between the chamber and the pyrolysis tube, passing an inert gas through the chamber and through the pyrolysis tube, passing a reactive gas through the chamber and through the pyrolysis tube, sealing off the pyrolysis tube from the chamber, placing the samples in the chamber, closing the chamber, purging the chamber with an inert gas, introducing a reactive gas into the chamber, removing the gastight seal between the pyrolysis tube and the chamber, introducing the samples within the chamber into the pyrolysis tube in sequence until the samples have been analyzed, establishing a gastight seal between the chamber and the pyrolysis tube, introducing an inert gas into the chamber, and thereafter removing the sample carriers from the chamber. 